The MARC Animal Core will serve the Center by purchasing, testing, breeding, maintaining and distributing[unreadable] animals to MARC investigators. The Animal Core will serve five major purposes: (1) Purchase and set up[unreadable] breeders to produce animals for the MARC Scientific Components; (2) Behaviorally test mice associated[unreadable] with the creation of short-term selection lines to be used by Scientific Components 5 and 6 (3) Determine[unreadable] animal distribution priorities and develop distribution procedures; (4) Develop new behavioral testing[unreadable] procedures and obtain animals on an as needed basis for new pilot projects or changes in direction as they[unreadable] occur; (5) Maintain a database that will track individual animals and post trait data for all MARC investigators[unreadable] to view and utilize. F1 or F2 mice that are the descendents of C57BL/6J (B6) and DBA/2J (D2) inbred strain[unreadable] mice will be used in Scientific Components 5 and 6, and Pilot Project 8B. The Core will breed F1 and F2[unreadable] mice for use in these components. A set of replicated mouse lines selected for high and low[unreadable] methamphetamine (MA) drinking, and an independent set for high and low MA-induced sensitization will be[unreadable] created within the Animal Core for distribution to Scientific Components 5 and 6. B6 breeders will also be set[unreadable] up to produce the neonates to be treated in the Core for Pilot Project 8C. The Animal Core will be managed[unreadable] by Dr. John Crabbe, who is experienced in developing animal models of addiction, and will be capable of[unreadable] providing other strains or genotypes of mice for new pilots on an as needed basis. All animals will be housed[unreadable] in AALAC accredited animal facilities under the full-time supervision of a licensed veterinarian. Procedures[unreadable] are in place for the avoidance of viral and bacterial contamination, and a sentinel screening program is used[unreadable] to quickly identify contamination and avoid spread. Careful genetic record-keeping and identification[unreadable] practices for the maintenance of a large number of genotypes have been in place for several years. Key[unreadable] advantages of the Animal Core are cost savings associated with centralized development, behavioral testing[unreadable] and distribution of the selected line mice; controlled environmental conditions; genetic quality control;[unreadable] removal of animal production burden from Component Pis. Decisions about animal distribution will be[unreadable] centralized and based on a number of criteria, including date of request, whether the request is for a MARC[unreadable] project, scientific progress, and date of last distribution to that project. The Core will be able to distribute[unreadable] littermates across projects to minimize litter effects within studies, and increase the potential for crossexperiment[unreadable] association analyses. Core practices will strengthen the data generated by the MARC.